Breathing protective device

ABSTRACT

A breathing protective device comprises a filter house body ( 1 ) having a filter house ( 8 ) with a filter house chamber ( 40 ) and a first wall section ( 45 ) having a number of through holes ( 47, 47   a ), at least one filter ( 2 ) in the filter house chamber inside said first wall section, and a mouthpiece ( 9 ) arranged to be introduced into and held in the user&#39;s mouth and having an air passage between an opening ( 53 ) in a second wall section ( 46 ) in the filter house ( 8 ) and an opening ( 54 ) at the end that is to be introduced into the user&#39;s mouth. The distinguishing features are that the filter house ( 8 ) has a first end ( 5 ), a second end ( 7 ) and said first and second wall section ( 45, 46 ) that extend between said ends of the filter house, that the filter house is elongated and extends parallel to a line between the corners of the user&#39;s mouth when the mouthpiece is inserted in the user&#39;s mouth, that said first wall section of the filter house is provided with a plurality of through holes ( 47, 47   a ) in at least one area and that it extends at least essentially straight in the longitudinal direction of the house at least on the inside in at least the area or areas in which said through holes are arranged, that the filter is arranged in the filter house chamber, along said second wall section and covering the openings in this wall section, that a non return valve ( 3, 33 ) that is closed at inhalation and opened at exhalation is arranged in at least said first end, and that at least one passage ( 40 ) for exhalation air extends between the opening in the first wall of the filter house and said non return valve at the first end of the filter house.

TECHNICAL FIELD

The invention relates to a breathing protective device comprising afilter house body having a filter house with a filter house chamber anda first wall section having a number of through holes, at least onefilter in the filter house chamber inside said first wall section and amouthpiece arranged to be introduced into and held in the user's mouthand having an air passage between an opening in a second wall section inthe filter house and an opening at the end that is to be introduced intothe user's mouth.

BACKGROUND OF THE INVENTION

Breathing protective devices used today are either very advanced butconventional gas masks, or more simple breathing protective devices thatcover the mouth and nose. Gas masks have their given field of use inextremely dangerous environments that require advanced air purification.Simple, conventional breathing protective devices that cover the mouthand nose are widely used for lack of anything else, in environments alsorequiring air purification, despite such devices being uncomfortable andin many cases having insufficient purification ability and otherdrawbacks.

Breathing protective devices of the type mentioned in the introductionabove have also been suggested. As examples of such breathing protectivedevices reference can be made to those described in WO 92/21408, EP 0695 561 A1, U.S. Pat. No. 5,771,885, U.S. Pat. No. 5,957,131 and DE-OS 2115 715. However, all protective devices shown in these publicationshave deficiencies and/or drawbacks and have as far as the applicant isaware not come to any wide use.

BRIEF ACCOUNT OF THE INVENTION

Given the above background, the invention aims at providing a breathingprotective device of the type mentioned in the introduction above, whichin combination with a nose clip, nose plugs or similar will provide fora perfectly satisfactory protection in many work environments and thathas many practical advantages in addition. More specifically, theinvention aims at providing a breathing protective device that fulfilsmost of the following advantages and/or requirements:

-   -   A good purifying effect    -   A small breathing resistance both at inhalation and at        exhalation    -   A small size (pocket-size)    -   A low weight    -   No interference with the users visual field; not having any far        projecting parts    -   Can be used by persons having a mustache or beard    -   Standard filters can be used    -   Can be rationally produced    -   The filter is easy to insert and remove for exchange or cleaning    -   A large degree of utilization of space available for air        purification    -   Can be used with different filter grades adapted to the        requirements of the environment of use    -   Does not require a special cassette for insertion and removing        of the filter    -   By a small modification, the same basic design can be used also        to clean exhalation air, e.g. to filter micro-organisms from the        exhalation air.

All, or at least most of the qualities mentioned above can be attainedby a breathing protective device of the type mentioned in theintroduction, characterised in

-   -   that the filter house has a first end, a second end and said        first wall section that extends between said ends of the filter        house,    -   that the filter house is elongated and extends parallel to a        line between the corners of the user's mouth when the mouthpiece        is inserted in the user's mouth,    -   that said first wall section of the filter house is provided        with a plurality of through holes in at least one area and that        it extends at least essentially straight in the longitudinal        direction of the house at least on the inside in at least the        area or areas in which said through holes are arranged,    -   that the filter is arranged in the filter house chamber, along        said second wall section and covering the openings in this wall        section,    -   that a non return valve that closes at inhalation and opens at        exhalation is arranged in at least said first end, and    -   that at least one passage for exhalation air extends between the        opening in the first wall of the filter house and said non        return valve at the first end of the filter house.

Additional characteristics and aspects of the invention are apparentfrom the claims and from the following detailed description of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the detailed description of the invention, reference will be made tothe enclosed drawings, of which

FIG. 1 shows a planar view of a filter of a type that can be used in thebreathing protective device according to the invention,

FIG. 2 is a side elevation view of the filter along a line II-II in FIG.1,

FIG. 3 is an exploded view in perspective showing the differentcomponents that are part of the breathing protective device according toa preferred embodiment of the invention,

FIG. 5 is an end elevation view of the filter house along a line V-V inFIG. 3,

FIG. 6 shows the assembled breathing protective device in a sideelevation view in a direction towards a rear mouthpiece opening,

FIG. 4 shows the breathing protective device in side elevation along theline IV-IV in FIG. 6, and

FIG. 8 shows an encircled part of FIG. 7 in a larger scale, and FIG. 7in turn shows the cross section VII-VII of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

According to the preferred embodiment of the invention, a breathingprotective device consists of a filter house body 1 having a filterhouse 8, a filter 2 that can be introduced into the filter house 8, avalve body 3 and a cover 4. The valve body 3 is arranged to be mountedat a first end 5 of the filter house 8. The filter 2 can be introducedinto the filter house 8, via an opening 6 at the second end 7 of thefilter house, and the cover 4 is intended to seal the opening 6 when thefilter 2 has been introduced.

FIGS. 1 and 2 show the filter 2 in an initial position, before it hasbeen introduced into the filter house 8. In this form, it consists of asmall rectangular sheet (the terms plate or cloth can also be chosen foran object of this type), having a length of 90 mm, a width of 65 mm anda thickness of about 5 mm. A pair of longitudinal side edges have beendenoted 10, 11 and a pair of opposite end edges have been denoted 12 and13, respectively. The sheet has been punched or cut out from a largersheet of a type of multilayered filter cloth that is manufactured byHullingsworth & Vose Filtration Ltd, England, under the trade nameTechnostat, 200 gr/m². The filter 2 used according to the preferredembodiment is accordingly a filter cloth of standard type, that iswidely used in fixed filters at industrial premises, in vacuum cleanersetc. This filter cloth, and thereby also the filter 2, consists of anouter, relatively rigid but pliable, flexible supporting layer 15 of acoarse plastic net, inside of that a filter stuff 16 of soft, fibrous,mixed synthetic material, and innermost at the suction side a very thinscreen cloth 17 of spun polypropylene, that prevents fluff from thefilter stuff 16 to come loose and be sucked into the user's mouth. Thenet-shaped supporting layer 15 is manufactured from thin, crossedstrands of plastic that are positioned on top of each other but notbraided together. More specifically, the net-shaped supporting layer 15has upper strands 18 and lower strands 19, the latter bearing againstthe filter stuff 16 that forms the actual filtering layer. This alsomeans that all openings 20 between each pair of adjacent outer strands18 are in direct communication with each other, and that essentially allopenings 21 between each pair of lower strands 19 also are incommunication with each other, which is not without significance to thedistribution of the air that is sucked into the filter stuff/filteringlayer 16.

The described type of filter, having the trade name Technostat, 200gr/m² is suitable when the breathing protective device according to theinvention is to be used e.g. in dusty construction sites or by personshaving allergy troubles for e.g. canine, feline or bovine hair orpollen. In environments containing cement powder, stone and/or carbondust, a filter stuff should be used that is finer than the one inTechnostat, 200 gr/m², in which case the filter however may have thesame design as the described one and be manufactured by the companymentioned above or some other manufacturer. In principle, still finerfilter stuffs can be used in the filter that is part of the breathingprotective device according to the invention, e.g. filter stuffscontaining activated carbon, ion-exchanger materials or other absorbentsor adsorbents for uptake of gaseous or vaporous pollutants, as well aswelding fume and other fumes.

The filter house body 1 is an integrated unity of moulded plasticsconsisting of said filter house 8 and a mouthpiece unit 9. The filterhouse 8 is shaped as an elongated, circular-cylindrical tube thatextends between said first end 5 and said second end 7 with an opening 6that can be covered by the cover 4. In this embodiment, the filter house8, including the cover 4, has a total length of 100 mm, an outerdiameter of 33 mm and a wall thickness of about 2 mm.

A central, cylindrical recess 30 is arranged at the first end 5 of thefilter house 8, FIG. 4 and FIG. 6. At the bottom of the recess 30, thereare four openings 31 for exhalation air and shaped as circular sectors,between four radial spars 32. Around the bottom of the circumference ofthe recess 30, there is also an annular shelf 33. The spars 32 and theannular shelf 33 together form a seat for the valve body 3 that consistsof a rubber membrane. At the centre of the rubber membrane there is apin 34 and at the end of the pin there is a knob 35 that can be snappedinto a central hole 36 at the bottom of the recess 30 to fix the valvebody 3 in said recess. This valve design is of a standard type used ine.g. diving gears. At inhalation, this non return valve is sealed by themembrane 3, having a diameter corresponding to the diameter of therecess 30, sealing against the shelf 33 and also resting against thespars 32.

A filter house chamber 40 is arranged in the filter house 8. At theinside of the filter house 8, there are two fins 41, 42 that initiallyextend radially inwards from the filter house wall, in order then tobend off at straight angle in opposite directions from each other. Thearc distance between the fins 41 and 42 comprises a circular sectorangle of 90°. The fins 41, 42 extend along the entire length of thefilter house chamber 40, from said annular bottom 38 at the first end 5of the filter house 8, to the opening 6 at the second end 7 of thehouse. The fins 41, 42 form rails that constitute attachment means forthe filter 2 that can be fixed in the grooves 43 formed by the angledfins 41, 42 in combination with the wall on the filter house. Thesefins/rails/attachment means 41, 42 also form a border between a first,front wall section 45 in the filter house 8, which first wall section 45extends ahead from the first attachment means 41 and around the filterhouse 8 to the second attachment means 42, thus forming a 270° longcircular arc, and a second, rear wall section 46, comprising saidcircular arc of 90°. When the filter 2 is mounted, it is manually shapedto the approximate shape shown in FIG. 3, with the supporting layer 15outwards turned, where after the filter 2 is inserted through theopening 6 and into the filter house 8, whereby the longitudinal edges11, 12 of the filter 2 are inserted into the grooves 43 of theattachment means 41, 42. Thereafter, the filter 2 is pushed all the waythrough the filter house 8 with the edges 11, 12 sliding in the grooves43, until the first end edge 12 of the filter 2 abuts the annular bottom38 at the first end 5 of the filter house. Then, the second end edge 13of the filter 2 will be flush with the second end 7 of the filter house,or project a few millimetres from the opening 6. When the cover 4 isapplied, it will accordingly bear against the edge 13 of the filter atthe same time as the longitudinal edges 10, 11 bear against the bottomof the grooves 43 of the attachment means 41, 42.

In the first wall section 45, a plurality of holes 47 are provided forair to be sucked in and purified in the filter 2 that is arranged in thefilter house chamber 40 in the area of said first wall section 45. Onthe inside of the filter house 8, there is in said first wall section 45also a number of longitudinal projections 48 on the filter house wall.They extend along the entire length of the filter house and are five innumber. As is shown in FIGS. 3 and 6, the holes 47 in the filter housewall are arranged in longitudinal rows. The longitudinal projections 48are arranged between every second of these rows. The height of theprojections 48 is about 0.3 mm, which is enough to form a narrow slit 49between the filter house wall and the filter 2. In the space 49, the airthat is sucked in via the openings 47 is distributed before the air issucked further in, through the filter 2. The supporting layer 15 of thefilter may, by its above described design, also contribute to aneffective distribution of air on the air suction side of the filterstuff/filtering layer 16. The filter 2, that is fixed in the attachmentmeans 41, 42, is, by the resiliency in the supporting layer 15, pressedagainst the filter house wall, a priori against the longitudinalprojections 48 around the entire circular arc shaped inside of the firstwall section 45. The longitudinal edges 10, 11 of the filter are pressedagainst the bottom 43 in the attachment means 41, 42 and are in that waysealed, while the end edges 12, 13 are sealed against the annular endwall 38 at the first end 5 of the filter house, and against the insideof the cover 4 at the second end 7, respectively.

The mouth piece unit 9 is connected to the filter house 8 in the area ofthe second wall section 46 of the filter house, centrally on this wallsection, so that the filter house 8 projects equally far to the left asto the right from the mouth piece unit. According to the embodiment, themouth piece unit 9 has a symmetry plane 51 that coincides with alongitudinal symmetry plane for the filter house 8. The mouth piece 9comprises a tubular section 52, that forms a canal from a front opening53 in the second wall section 46 of the filter house to a rear,elongated opening 54. The opening 53 in the filter house wall issomewhat wider, as is apparent from FIG. 4. The tubular section 52 iselongated in the symmetry plane 51. The longitudinal side walls 56 areflat and parallel, while the end walls 57 are rounded, FIG. 3. Theconnection 58 to the filter house 8 is softly rounded up to all walls ofthe tubular section 52. From the opening 53, the filter house 8 projectsabout the same length in both directions.

The mouth piece 9 has a pair of wings 60, that extend obliquelybackwards and outwards from the rear end of the tubular section 52.These wings are inserted into the user's mouth and will then bearagainst the cheeks in the oral cavity. Thanks to the elongated extensionof the tubular section, the rounded end walls 57 of the tubular sectionwill furthermore bear against the corners of the mouth at the same timeas the lips grip the tubular section and a pair of arched flanges 61,one on each side of the opening 54 at the rear end of the planar walls56. Furthermore, the mouth piece with the tubular section 52 has such alength that the lips will bear against the rounded transition 58 to thefilter house 8, close to but not covering the openings 47a that arepositioned closest to the mouth piece 9. By the described elongatedshape of the tubular section 52 of the mouth piece 9, the rounded endwalls 52 are forced to locate themselves in the corners of the user'smouth, which in turn leads to that the entire filter house body 1 isoriented in a desired way, namely so that the filter house 8 will extendhorizontally crosswise in front of the user's mouth, with sections ofthe filter house projecting sideways in both directions, past thecorners of the mouth. In a direction forwards from the mouth, the filterhouse 1 and thus the entire breathing protective device only projects adistance corresponding approximately to the diameter 9 of the filterhouse, i.e. only just under 35 mm according to the embodiment, which isa considerable advantage in many work situations.

The described breathing protective device has such shape and accordingto the embodiment also such dimensions that it can be kept in a smallbag, that can be attached e.g. to a belt, or even in a pocket in thework-clothes of the user. When the breathing protective device is to beused, the mouth piece 9 is inserted into the user's mouth, as isdescribed above, while the nostrils are sealed in a conventional way,e.g. by a nose clip that can be attached in a hole 70 in the valve housewall, when the breathing protective device is not used. When the userinhales, the non return valve at the first end 5 of the valve house 8seals by the membrane 3 sealing against the circumferential shelf 33 inthe recess 30, at the same time as it is brought to bear against thespars 32. Air is sucked in via the openings 47, 47 a and is distributedin the slit 49 on the inside of the filter house wall in the first wallsection 45, before the air continues to be sucked in through the filterstuff/filtering layer 16 and further into the space inside the filter 2in the filter house chamber 40. From there, the air continues throughthe opening 53, the tubular section 52 and the rear opening 54 in themouthpiece, and into the user. The breathing resistance caused by thebreathing filter is small, especially in relation to the smalldimensions of the breathing protective device. This is due to the filter2 having a comparatively large surface, that can be fully used by anoptimal utilisation of the design and geometry of the breathingprotective device. The efficient distribution over the filter surface,of the air that is sucked in, also promotes a low breathing resistance.At exhalation, the breathing resistance of the breathing protectivedevice is virtually negligible. The air channels that consist of thetubular section 52 and of the filter house chamber 40 inside the filter2 are very wide; the membrane 3 opens up at an extremely lowoverpressure and also, the air discharge openings 31 at the first end 5of the filter house are wide enough not to cause any noticeableresistance.

It should be realised that the design of the breathing protective deviceis not limited to the embodiment described, but may be varied within thescope of the enclosed claims. Accordingly, the filter house 8 e.g. maybe of another shape than a circular cylindrical tube, e.g. a tube withan orthogonal cross-section. However, the circular cylindrical shapeought to be ideal. It is also conceivable to angle the connectingtubular piece 52 downwards, so that the filter house 1 will bepositioned at a lower lever, somewhat below the opening of the mouth.This would however increase the entire size of the breathing protectivedevice, which is a drawback. Furthermore, the openings 47, 47 a in thefilter house wall can of course be given another shape and size than theshown one, without impairing the function of the breathing protectivedevice in any way, given that the total area of the inlet openings isnot decreased too much. It should also be mentioned that the filter 2can be of another type than the described one. Instead of being pliableand able to be formed from a planar piece, it may accordingly be stiffand have the shape it should have in a functional position in the filterhouse chamber, something that in certain cases possibly may be aprerequisite for it to be used in certain types of filter stuffs. Inprinciple, the filter 2 may be arranged in a cassette, even though it isa clear advantage not having to use such an extra component but insteadavoiding any type of cassette or the similar, which the embodimentconstitutes an example of. Another alternative is to make the filternon-exchangeable, so that the entire breathing protective device isexchanged when it is considered to be consumed. Hereby, the filter ispreferably integrated (e.g. in connection with moulding) in the filterhouse, during the manufacturing process.

1-19. (canceled)
 20. A breathing protective device comprising a filterhouse body having a filter house with a filter house chamber and a firstwall section having a number of through holes, at least one filter inthe filter house chamber inside said first wall section, and amouthpiece arranged to be introduced into and held in the user's mouthand having an air passage between an opening in a second wall section inthe filter house and an opening at the end that is to be introduced intothe user's mouth: wherein the filter house has a first end, a second endand said first and second wall section that extend between said ends ofthe filter house, the filter house is elongated and extends parallel toa line between the corners of the user's mouth when the mouthpiece isinserted in the user's mouth, said first wall section of the filterhouse is provided with a plurality of through holes in at least one areaand that it extends at least essentially straight in the longitudinaldirection of the house at least on the inside in at least the area orareas in which said through holes are arranged, the filter is arrangedin the filter house chamber, along said second wall section and coveringthe openings in this wall section, a non return valve that is closed atinhalation and opened at exhalation is arranged in at least said firstend, and at least one passage for exhalation air extends between theopening in the first wall of the filter house and said non return valveat the first end of the filter house.
 21. A breathing protective deviceaccording to claim 20, wherein said first wall section of the filterhouse has an inside that is essentially straight in the longitudinaldirection of the filter house but arched, bent or angled in a plane thatis perpendicular to the longitudinal direction.
 22. A breathingprotective device according to claim 20, wherein the inside of saidfirst wall section defines a cylindrical segment of the filter housechamber, that extends along at least the major part of the length of thefilter house chamber and around at least the major part of itscircumference, from a first position on one side of the opening in saidsecond wall section, around the inside of said first section to a secondposition on the other side of said opening.
 23. A breathing protectivedevice according to claim 20, wherein the length of the innercircumference of the first wall section is longer than the circumferenceof the wall section in the areas between the opening of this end sectionand said ends.
 24. A breathing protective device according to claim 21,wherein the inside of said first wall section is essentially circularcylindrical.
 25. A breathing protective device according to claim 20,wherein attachment means for the filter are arranged on the inside ofthe filter house.
 26. A breathing protective device according to claim25, wherein said attachment means are arranged at said first and secondpositions on either side of and preferably close to the opening in saidsecond wall section.
 27. A breathing protective device according toclaim 26, wherein the attachment means for the filter are designed asrails that, connected to the filter house wall, extend in thelongitudinal direction of the filter house, along the entire length ofsaid first wall section, and form longitudinal boundaries for this wallsection and at the same time form seals against the longitudinal edgesof the filter.
 28. A breathing protective device according to claim 27,wherein the longitudinal edges of the filter are arranged in grooves insaid attachment means.
 29. A breathing protective device according toclaim 20, wherein the filter, when mounted in the filter house chamber,has an outside contour that essentially follows the inside contour ofthe first wall section of the filter house.
 30. A breathing protectivedevice according to claim 29, wherein the filter is fixed between saidattachment means to bear against or almost bear against the inside ofthe first wall section of the filter house.
 31. A breathing protectivedevice according to claim 30, wherein the filter comprises both afiltering layer that contains a filter stuff and a supporting layer thatis flexibly pliable and relatively stiff and has a plurality of openingsarranged close to each other, which supporting layer forms a firstdistance means between the filter house wall and the filtering layer.32. A breathing protective device according to claim 31, wherein thefirst wall section of the filter chamber is on its inside provided witha plurality of low height projections that form second distance meansbetween the filter house wall and the filtering layer.
 33. A breathingprotective device according to claim 31, wherein each opening in thesupporting layer communicates with another opening in the supportinglayer, such that a distribution of the air can be promoted thereby,before the air is sucked into the filtering layer.
 34. A breathingprotective device according to claim 32, wherein the supporting layer isdesigned as a relatively coarse mesh plastic net formed of upper andlower, crossed strands.
 35. A breathing protective device according toclaim 20, wherein a recess is provided at said first end, on the outsideof the filter house, and in that the non return valve is recessed andfixed in this recess.
 36. A breathing protective device according toclaim 20, wherein an end wall section is provided at the first end ofthe filter house, all around the inside of the filter house, againstwhich end wall section one end edge of the filter bears.
 37. A breathingprotective device according to claim 35, wherein a seat for a membraneincluded in said non return valve is provided at the bottom of therecess at said first end.
 38. A breathing protective device according toclaim 20, wherein a detachable cover covers an opening at the second endof the filter house, the filter via said opening can be inserted in thefilter house chamber, and the inside of the cover bears against thesecond end wall of the filter, after it has been put back over theopening.